Anaphylaxis In Patients Research Articles

Gelatin-Containing Vaccines for Varicella, Zoster, Measles, Mumps, and Rubella Induce Basophil Activation in Patients with Alpha-Gal Syndrome

Background: The alpha-gal syndrome (AGS) describes a new type I allergy entity to the carbohydrate epitope galactose-α-1,3-galactose (alpha-gal), which is mainly found in mammalian food products (e.g., beef, pork, and venison). Apart from meat products, alpha-gal can also be found in products containing gelatin of bovine or porcine origin. Recent case reports pointed to severe anaphylaxis in patients suffering from AGS after vaccination with vaccines containing hydrolyzed gelatin. It was the objective of this study to evaluate if basophil activation tests (BATs) performed with such vaccines were positive in patients with AGS. Methods: BAT was performed with different dilutions of a gelatin-containing measles, mumps, and rubella (MMR) live vaccine; an attenuated varicella (V) vaccine; an attenuated V-zoster (VZ) vaccine; a MMR live vaccine not containing gelatin (non-gelatin MMR vaccine) in 2 patients with confirmed AGS, 2 patients highly suspicious for AGS, and 2 healthy individuals without any previous medical history for allergies. Results: All patients showed strongly positive results for all gelatin-containing vaccines (MMR vaccine, V vaccine, and VZ vaccine). Non-gelatin MMR vaccine was negative. The 2 healthy controls did not show any basophil activation. Conclusions: Gelatin-containing vaccines should be administered with caution or avoided in patients with AGS because of their high potential to activate basophils indicating a risk for anaphylaxis. Also, BAT is a useful additional tool when it comes to screening for potentially high-risk alpha-gal-containing drugs.

Effect of Prescription Drugs on Anaphylaxis Severity and Symptoms

Anaphylactic reactions are medical emergencies presenting with varying levels of severity, which may be influenced by drug intake. We aimed to assess the severity of anaphylaxis in patients taking statins, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, tricyclic antidepressants as well as proton-pump inhibitors.

Relationship of perioperative anaphylaxis to neuromuscular blocking agents, obesity, and pholcodine consumption: a case-control study

BackgroundThe observation that patients presenting for bariatric surgery had a high incidence of neuromuscular blocking agent (NMBA) anaphylaxis prompted this restricted case-control study to test the hypothesis that obesity is a risk factor for NMBA anaphylaxis, independent of differences in pholcodine consumption. MethodsWe compared 145 patients diagnosed with intraoperative NMBA anaphylaxis in Western Australia between 2012 and 2020 with 61 patients with cefazolin anaphylaxis with respect to BMI grade, history of pholcodine consumption, sex, age, comorbid disease, and NMBA type and dose. Confounding was assessed by stratification and binomial logistic regression. ResultsObesity (odds ratio [OR]=2.96, χ2=11.7, P=0.001), ‘definite’ pholcodine consumption (OR=14.0, χ2=2.6, P<0.001), and female sex (OR=2.70, χ2=9.61, P=0.002) were statistically significant risk factors for NMBA anaphylaxis on univariate analysis. The risk of NMBA anaphylaxis increased with BMI grade. Confounding analysis indicated that both obesity and pholcodine consumption remained important risk factors after correction for confounding, but that sex did not. The relative rate of rocuronium anaphylaxis was estimated to be 3.0 times that of vecuronium using controls as an estimate of market share, and the risk of NMBA anaphylaxis in patients presenting for bariatric surgery was 8.8 times the expected rate (74.9 vs 8.5 per 100 000 anaesthetic procedures). ConclusionsObesity is a risk factor for NMBA anaphylaxis, the risk increasing with BMI grade. Pholcodine consumption is also a risk factor, and this is consistent with the pholcodine hypothesis. Rocuronium use is associated with an increased risk of anaphylaxis compared with vecuronium in this population.

Comorbidities and Cofactors of Anaphylaxis in Patients with Moderate to Severe Anaphylaxis. Analysis of Data from the Anaphylaxis Registry for West Pomerania Province, Poland.

Anaphylaxis is a severe, potentially life-threatening systemic hypersensitivity reaction that is still rarely diagnosed. For safety reasons, patients should visit an allergologist to identify potential causes and cofactors of this reaction. This paper presents the analysis of data from the Anaphylaxis Registry gathered over ten years at the Allergy Clinic, Pomeranian Medical University (PMU). A questionnaire-based survey was used for patients visiting the Allergy Clinic to identify potential augmentation factors/comorbidities and/or cofactors of anaphylaxis in patients with a history of moderate to severe anaphylaxis. The registry comprised patients with grade II or higher anaphylaxis. The gathered data concerned chronic comorbidities (cardiovascular diseases, respiratory diseases, and others), recurrence of anaphylaxis, and potential cofactors in anaphylaxis. In the analyzed group, the incidence rate of anaphylaxis was the highest for women aged 19–60 years. Most common comorbidities in patients with moderate to severe anaphylaxis included: cardiovascular diseases, respiratory tract diseases, features of atopy, and thyroid diseases. More than 30% of drug-induced reactions were anaphylactic reactions due to the re-exposure to the same drug, which points to the need for educational initiatives in this area. The incidence rate of anaphylaxis induced by Hymenoptera stings was comparable in patients who had a previous generalized reaction and those who had good tolerance to the previous sting. It is important to take these cofactors into consideration when evaluating patients with anaphylaxis as they may play a role in future anaphylactic reactions.

The association between neutrophil-to-lymphocyte ratio and anaphylaxis refractory to epinephrine treatment

Objectives: Anaphylaxis refractory to epinephrine treatment is a potentially fatal condition requiring additional medications. Neutrophil-to lymphocyte ratio (NLR) is commonly used to predict severity in allergic diseases. The aim of this study was to determine the association between NLR and refractory anaphylaxis. Methods: This was a retrospective, observational study of 126 adult anaphylaxis patients arriving at the emergency department between January 2015 and December 2019. Patients were placed into refractory anaphylaxis, if they required more than two 0.3 mg injections of intramuscular epinephrine for symptom resolution, and non-refractory anaphylaxis groups. NLRs were determined at the time of arrival at the hospital and were compared between groups. Results: Thirty-two (25.4%) patients were categorized as refractory anaphylaxis cases. NLR was significantly lower in the refractory anaphylaxis than in the non-refractory anaphylaxis group (P &lt; 0.001). In the multivariate logistic regression analysis model, NLR was inversely associated with the occurrence of refractory anaphylaxis (adjusted odds ratio 0.33, 95% confidence interval 0.13-0.81, P = 0.016). The area under the receiver operating characteristic curve of NLR for prediction of refractory anaphylaxis was 0.717 (P &lt; 0.001). The optimal cut-off value of NLR was &lt; 0.68 using the Youden index, with 50.0% sensitivity and 80.9% specificity. Conclusions: NLR was independently and inversely associated with the occurrence of refractory anaphylaxis among anaphylactic patients. Therefore, NLR has the potential to be used as an easy and inexpensive test to predict refractory anaphylaxis in patients.

Pediatric Anaphylaxis: Etiology and Predictive Factors in an Emergency Setting.

Anaphylaxis is a serious allergic life-threatening condition that needs immediate treatment to prevent unfavorable outcomes. The present study revealed that the prevalence of anaphylaxis in children increased with age and the adolescent group has the most frequent anaphylaxis events. Food-induced anaphylaxis was the most common cause of anaphylaxis in pediatric population. This etiology revealed a significant correlation with a known history of food allergy in the study population, P = .029. Anaphylaxis from insect stings associated with cardiovascular symptoms, P < .001 and inclined to be severe. Univariate analysis showed predicted probability of severe anaphylaxis increased with age with an odds ratio of 1.1. This finding strengthens and supports the view that physicians should be aware of severe anaphylaxis reactions in older age group when there is a documented history of insect sting. The overall pediatric anaphylaxis patients in the study population had favorable outcomes. The authors recommended at least 24 hours hospital observation in order to observe biphasic reaction in pediatric anaphylaxis especially in adolescent age group.

Demographic, clinical and diagnostic correlation of almond allergy in a cohort of nut allergy patients

ABSTRACTTree nut anaphylaxis commonly categorizes almond as a potential allergen. However, large studies on allergic cohorts focused on almond allergy are rare. Food allergy is increasing globally. In parallel, almond consumption is increasing in developed nations. This study presents serological data in a large paediatric cohort of food anaphylaxis patients specifically assessing almond allergy risk. The purpose of this study is to describe the correlation of almond allergy specific to demographic, clinical and diagnostic markers in a cohort of 411 nut-allergic children. In this cohort with a history of food allergy, the prevalence of almond allergy was 67.6%. Approximately 25% of patients demonstrated both almond sensitivity (sIgE > 0.35 kU/L) and clinical reactivity (wheal size > 3 mm). Interestingly, peanut allergy was listed in the top 3 allergens of 71.8% of patients with almond sensitivity and reactivity. A better understanding of these relationships is essential as more patients are receiving personalized care.

Patient/parent administered epinephrine in acute anaphylaxis.

Among patients with a known peanut allergy, previous studies suggest low carrying rates of epinephrine auto-injectors (EAIs) and hesitancy to self-administer epinephrine upon anaphylaxis onset. Given the high prescription rates of epinephrine and prevalence of peanut allergies, it is important to identify rates of on-scene EAI use and affecting factors. The electronic medical records of 217 patients-either with an ED diagnosis of peanut anaphylaxis or diagnosis of anaphylaxis with a known epinephrine prescription from 2010 through May 2020--were reviewed for physician notes and demographic factors. Epinephrine was administered on-scene by 25.3% of anaphylaxis patients. Of the 6 health care professionals identified, 100% administered epinephrine on-scene. Females (32.2%) were administered epinephrine on-scene more frequently than males (19.8%; p=0.04). Rate of epinephrine administration increased from 2010 through 2019 (p=0.005). This study selected for individuals diagnosed with anaphylaxis, meaning EAI use should have been observed nearly 100% of the time. An administration rate of 22.6% observed among individuals not identified as health care professionals suggests that the majority of patients prescribed epinephrine have not used their EAIs, even when presented an opportunity for application. The administration rate of 100% observed among health care professionals indicates that comfort with EAIs facilitates willingness to administer on-scene. EAIs can range up to $900 in expense, thus physicians should employ EAI training devices and other training strategies.

Assessment of ED triage of anaphylaxis patients based on the Emergency Severity Index

To describe the emergency department (ED) triage of anaphylaxis patients based on the Emergency Severity Index (ESI), assess the association between ESI triage level and ED epinephrine administration, and determine characteristics associated with lower acuity triage ESI assignment (levels 3 and 4). We conducted a cohort study of adult and pediatric anaphylaxis patients between September 2010 and September 2018 at an academic ED. Patient characteristics and management were compared between Emergency Severity Index (ESI) triage level 1 or 2 versus levels 3 or 4 using logistic regression analysis. We adhered to STROBE reporting guidelines. A total of 1090 patient visits were included. There were 26 (2%), 515 (47%), 489 (45%), and 60 (6%) visits that were assigned an ESI triage level of 1, 2, 3, and 4, respectively. Epinephrine was administered in the ED to 53% of patients triaged ESI level 1 or 2 and to 40% of patients triaged ESI level 3 or 4. Patients who were assigned a lower acuity ESI level of 3 or 4 had a longer median time from ED arrival to epinephrine administration compared to those with a higher acuity ESI level of 1 or 2 (28min compared to 13min, p<.001). A lower acuity ESI level was more likely to be assigned to visits with a chief concern of hives, rash, or pruritus (OR 2.33 [95% CI, 1.20-4.53]) and less likely to be assigned to visits among adults (OR, 0.43 [0.31-0.60]), patients who received epinephrine from emergency medical services (OR 0.56 [0.38-0.82]), presented with posterior pharyngeal or uvular angioedema (OR, 0.56 [0.38-0.82]), hypoxemia (OR, 0.34 [0.18-0.64]), or increased heart (OR 0.83 [0.73-0.95]) or respiratory (OR 0.70 [0.60-0.82]) rates. Patients triaged to lower acuity ESI levels experienced delays in ED epinephrine administration. Adult and pediatric patients with skin-related chief concerns were more likely to be to be assigned lower acuity ESI levels. Further studies are needed to identify interventions that will improve ED anaphylaxis triage.

Recurring Anaphylaxis: A New Line of Questioning for your HPI

Anaphylaxis is a serious life-threatening allergic reaction that typically has an immediate onset. It can present as flushing, angioedema, shortness of breath, rash and result in death if not treated immediately. In the past ten years, an emerging cause of delayed anaphylaxis has been identified. An IgE antibody to a mammalian oligosaccharide epitope (alpha-gal, or galactose-alpha-1,3-galactose) has been linked to both immediate and delayed onset anaphylaxis. The immediate form is associated with the first exposure to cetuximab; whereas the delayed onset occurs after ingestion of mammalian meat such as beef and pork. The presentation can develop 2-6 hours after ingestion. This IgE antibody to alpha-gal is strongly suggested that Lone Star tick bites have been the culprit. It is imperative when caring for an anaphylaxis patient of unknown etiology, to consider a line of questioning to not only include recent tick bites, but also last 2-3 meals ingested to identify if mammalian meat may have been the trigger.

Acute emotional stress proposed as a risk factor for anaphylaxis in patients receiving allergen immunotherapy

Acute emotional stress proposed as a risk factor for anaphylaxis in patients receiving allergen immunotherapy

ADULT ANAPHYLAXIS AT THE DEPARTMENT OF EMERGENCY MEDICINE OF TEIKYO UNIVERSITY HOSPITAL IN AN URBAN AREA OF TOKYO

Anaphylaxis is a severe, potentially fatal, systemic allergic reaction. But its real-world evidence is limited. Both treatment of allergic symptoms and prevention of future anaphylactic episodes are clinically important. We have strongly recommended that patients visit our outpatient allergy clinic. To classify the clinical features and triggers of anaphylaxis in patients (≥16 years old) in an urban area of Tokyo. We used the medical records to analyze patients with anaphylaxis as the primary diagnosis who visited the emergency department in our hospital from January 2015 through December 2017. Among approximately 60000 patients who visited the emergency department, 181 subjects (mean age, 43.0; 44% male) were diagnosed with anaphylaxis. Fourteen of those patients had a systolic blood pressure of lower than 90mmHg. Upon arrival, 126 patients were treated with adrenaline. All patients recovered from the anaphylactic episode. Subsequently, 133 patients visited our outpatient allergy clinic. The trigger of the anaphylaxis were assessed; the most popular trigger was foods (n = 78), followed by drugs (n = 38), insect stings/bites or animal bites (n = 3) and others (n = 11). Adrenaline auto-injectors were prescribed to 84 patients. It is important for patients with anaphylaxis to undergo allergy testing after discharge from an emergency department. Collaboration between emergency medicine and allergy departments may be helpful for improving the patients' QOL through effective instruction and prevention of recurrent anaphylaxis.

Banana anaphylaxis in Thailand: case series

BackgroundBanana fruit has been recognized as an important food allergen source. Nowadays banana hypersensitivity had been reported more frequently with various presentations from oral allergy syndrome to anaphylaxis.ObjectiveThis study aims to describe the pattern of banana hypersensitivity and the sensitivity of diagnostic test.MethodsSix patients who experienced banana hypersensitivity were recruited from adult allergy clinic, Ramathibodi Hospital, Mahidol University between 2015–2018. Demographic data, pattern of banana allergy consisted of the onset of reaction, symptoms, severity, cross-reactivity to kiwi, avocado, latex including type and amount of banana were collected. Skin test, serum specific IgE to banana and open-label food challenge test had been applied.ResultsAll patients experienced multiple episodes of banana anaphylaxis. Regarding the diagnostic investigation, prick-to-prick skin test had higher sensitivity (sensitivity, 100%; 95% confidence interval [CI], 54.07%–100%) than the commercial banana extract (sensitivity, 83.33%; 95% CI, 35.88%–99.58%) and serum specific IgE to banana (sensitivity, 50%; 95% CI, 11.81%–88.19%). The discordance between skin prick test using commercial banana extract and skin test was reported. The cross-reactivity between the species of banana, kiwi, the avocado was documented in all patients. Latex skin prick test and application test were applied with negative results. From the oral food challenge test, a case of banana anaphylaxis patient can tolerate heated banana.ConclusionThe various phenotypes of banana hypersensitivity were identified. The prick-to-prick test showed the highest sensitivity for diagnosis of banana allergy. However, component resolved diagnostics might be needed for conclusive diagnosis.

Anaphylaxie à l’arachide par voie inhalée, à propos de 3 cas

Paradoxically, some dispute surrounds the risk of anaphylaxis through inhalation of peanut fragments and the literature contains only rare reports. Herein we describe 3 cases of inhaled peanut anaphylaxis in patients with a strong allergic phenotype: 2 cases of adolescents coming into contact with peanuts in public places (cinema, train) on two occasions, and a third case in a child receiving peanut immune tolerance induction (ITI). Following published cases of inhaled peanut anaphylaxis and complaints by allergic patients, protective measures have been taken by airlines and in certain countries. However, it has recently been asserted that peanuts are not volatile and that the risk of reaction to inhalation is minimal at most! However, we believe it is important to protect patients with a strong phenotype and high anaphylactic risk and for whom social situations (travel, outings, etc.) present a potential danger. We feel that ITI should be proposed, coupled with therapeutic education, even though the limits of ITI were evident in our third patient.

One-day ultrarush desensitization for Hymenoptera venom anaphylaxis in patients with and without mast cell disorders with adjuvant omalizumab

Systemic hypersensitivity reactions to Hymenoptera venom occur in 1.2% to 3.5% of the population. In patients with systemic mastocytosis, the incidence of Hymenoptera-induced systemic reactions is 20% to 50%, considerably greater than that in the general population.1 Fatalities are rare but have been reported in patients with and without mastocytosis.

Biphasic Reactions in Emergency Department Anaphylaxis Patients: A Prospective Cohort Study

Biphasic reaction rates and potential associated risk factors are not well understood. To evaluate biphasic reaction rates and associated risk factors. We prospectively enrolled patients with anaphylaxis at 2 Midwestern academic emergency departments (EDs). We gathered data using patient and ED provider surveys and a structured health record review. Biphasic reaction rates and clinically significant biphasic reaction rates, defined as recurrent reactions that met anaphylaxis diagnostic criteria or were treated with epinephrine, were calculated. Characteristics associated with biphasic reactions were assessed with logistic regression and reported with odds ratios (ORs) and 95% CIs. Of 430 ED anaphylaxis visits, 31 (7.2%) patients had biphasic reactions; 22 (5.1%) had clinically significant biphasic reactions. The median time from anaphylaxis onset to first epinephrine dose was longer for patients with biphasic (78 minutes) than uniphasic courses (45 minutes) (P= .005). A biphasic course was associated with an ED setting of first epinephrine dose (OR, 3.72; 95% CI, 1.36-10.14) and a delay of more than 30 minutes from symptom onset to first epinephrine dose (OR, 3.39; 95% CI, 1.13-10.18), and was inversely associated with arrival by ambulance (OR, 0.18; 95% CI, 0.05-0.61). A clinically significant biphasic reaction was associated with an ED setting of first epinephrine dose (OR, 3.32; 95% CI, 1.08-10.25) and inversely associated with arrival by ambulance (OR, 0.08; 95% CI, 0.01-0.61). Biphasic reactions and clinically significant biphasic reactions occurred in 7.2% and 5.1% of ED anaphylaxis patients, respectively. Delayed epinephrine administration was associated with biphasic reactions.

Secondary prevention measures in anaphylaxis patients: Data from the anaphylaxis registry.

Patients with a history of anaphylaxis are at risk of future anaphylactic reactions. Thus, secondary prevention measures are recommended for these patients to prevent or attenuate the next reaction. Data from the Anaphylaxis Registry were analyzed to identify secondary prevention measures offered to patients who experienced anaphylaxis. Our analysis included 7788 cases from 10 European countries and Brazil. The secondary prevention measures offered varied across the elicitors. A remarkable discrepancy was observed between prevention measures offered in specialized allergy centers (84% of patients were prescribed adrenaline autoinjectors following EAACI guidelines) and outside the centers: Here, EAACI guideline adherence was only 37%. In the multivariate analysis, the elicitor of the reaction, age of the patient, mastocytosis as comorbidity, severity of the reaction, and reimbursement/availability of the autoinjector influence physician's decision to prescribe one. Based on the low implementation of guidelines concerning secondary prevention measures outside of specialized allergy centers, our findings highlight the importance of these specialized centers and the requirement of better education for primary healthcare and emergency physicians.

Allergy and inhibitors in hemophilia - a rare complication with potential novel solutions

IntroductionHemophilia is a rare bleeding disorder caused by a deficiency of the plasma coagulation factors VIII and IX (hemophilia A [HA] and hemophilia B [HB], respectively). Replacement therapy with clotting factor concentrates is the mainstay of treatment. Unlike in patients with HB, anaphylaxis in patients with HA is extremely rare. MethodsA retrospective study of prospectively collected data on patients with hemophilia who experienced anaphylaxis was conducted in our center. Demographic and clinical data were collected, and laboratory workups that included thrombin generation were conducted. ResultsOur first patient underwent successful immune tolerance induction (ITI) following the administration of rituximab. The second patient was transitioned to emicizumab. The third patient receives recombinant activated VIIa (rFVIIa) on demand. Thrombin generation was performed following current medical management protocols for supporting hemostasis. DiscussionOur case series illustrates the difficulty in managing patients with anaphylaxis to replacement therapy. In the era of novel therapies, such as emicizumab, the management of HA patients who experience anaphylaxis to replacement therapy is becoming easier and may obviate the need for ITI. Current treatment strategies for HB patients with such anaphylaxis, however, are limited to rFVIIa, and it continues to pose a challenge.

306 Assessment of Emergency Department Anaphylaxis Patient Triage Based on the Emergency Severity Index

Early recognition and treatment of anaphylaxis is crucial. Delayed epinephrine administration for anaphylaxis allows progression of symptoms and has been associated with worse outcomes and increased mortality. Emergency department (ED) triage is a crucial step in management and ensures rapid assessment and resource allocation to the most critical patients. The Emergency Severity Index (ESI) is a common ED triage assessment tool that categorizes patients into one of five levels. Patients with the highest acuity are triaged as levels 1 and 2 while patients in levels 3, 4, and 5 are categorized based on expected resource utilization. The study objective was to assess ED triage of anaphylaxis patients and determine characteristics associated with higher versus (vs) lower triage levels. A cohort study including prospectively and retrospectively enrolled patients was conducted between 2010 and 2018 at a quaternary care academic ED with 77,000 annual patient visits. Patients were included if they met anaphylaxis diagnostic criteria for anaphylaxis. Patient health records were reviewed to evaluate patient demographics, inciting trigger, ESI triage level, out-of-hospital management, presenting signs and symptoms, ED management, and disposition. Prospectively enrolled patients and their ED providers also completed questionnaires regarding reaction characteristics and out-of-hospital treatment. Logistic regression analysis was performed to compare patient characteristics and management between patients triaged as ESI levels 1 or 2 vs levels 3 or 4. Data are summarized with descriptive statistics and corresponding odds ratios (ORs) with 95% confidence intervals (CIs). A total of 1104 patients met anaphylaxis diagnostic criteria and were eligible for study inclusion, of which 71% were enrolled retrospectively and 29% prospectively. The mean patient age was 34 years, 28% of patients were children (under 18 years of age), and 57% were female. Overall, 72% of patients received epinephrine (either prior to or after ED arrival). ESI triage levels of 1, 2, 3, 4, and 5 were assigned in 26 (2%), 517 (47%), 499 (45%), 62 (6%), and 0 (0%) of visits, respectively. There was no significant difference in ESI level assignment between prospectively and retrospectively enrolled patients. Patients assigned an ESI level of 3 or 4, compared to those with an ESI level of 1 or 2, had a longer median time from ED arrival to epinephrine administration (31 minutes [IQR 16-57] vs 13 minutes [IQR 7-13], [p < 0.01]), were more likely to be children (32% vs 24%; OR 1.50, 95% CI [1.15-1.96]), less likely to receive epinephrine in the ED (41% vs 53%; OR 0.62, 95% CI [0.49-0.78]), more likely to have an unidentified trigger (25% vs 18%; OR 1.45, 95% CI [1.08-1.93]), less likely to have angioedema (55% vs 63%; OR 0.74, 95% CI [0.58-0.94]) and less likely to report dyspnea (59% vs 66%; OR 0.74; 95% CI [0.58-0.94]), or throat tightness (45% vs 54%; OR 0.71; 95% CI [0.56-0.89]). An ESI triage level of 3 or 4 was associated with an increased time to epinephrine administration in patients presenting to the ED with anaphylaxis. Forty-one percent of patients triaged as ESI level 3 or 4 received epinephrine in the ED suggesting undertriage of a substantial proportion of anaphylaxis patients. Children and patients with an unidentified allergic trigger were more likely to be triaged as level 3 or 4.

Risk factors and prevention for perioperative anaphylaxis: a nested case-control study.

Background Perioperative anaphylaxis is rare but often severe. Little is known about the risk factors regarding perioperative anaphylaxis and the effect of anti-allergy premedication on prevention of perioperative anaphylaxis. Objective To identify the risk factors of perioperative anaphylaxis and to evaluate the prophylactic effects of anti-allergy premedication on perioperative anaphylaxis and investigate the factors associated with anti-allergy premedication options in patients who previously experienced anaphylaxis with unidentified culprits. Setting Surgical operation unit of the University Hospital in Chongqing, China. Method We identified patients who underwent surgery between Oct. 2012 and Dec. 2017. The study included two parts: in part one, a retrospective nested case-control study was used to identify the risk factors of perioperative anaphylaxis by logistic regression with 1 in 4 matching between patients with and without perioperative anaphylaxis; in part two, patients with high-risk anaphylaxis were included, in which patients who previously experienced anaphylaxis with unidentified culprits had been given anti-allergy premedication prior to the operation according to the degree of risk and severity of anaphylaxis. The prophylactic effects of anti-allergy premedication were evaluated and the factors associated with anti-allergy premedication options were explored. Main outcome measure Perioperative anaphylaxis occurrence. Results In part one, in the multivariate logistic analysis, history of drug allergy (OR 6.78; 95% CI, 2.35-19.54; P < 0.01) and history of allergies to food or other substances (OR 40.56; 95% CI, 8.12-202.52; P < 0.01) were associated with a higher risk of perioperative anaphylaxis. In part two, none of these patients either who had avoided culprits or who had been given anti-allergy premedication developed anaphylaxis during the surgical procedure. In the multivariate logistic model, history of grade II or grade III perioperative anaphylaxis (OR 9.09; 95% CI, 1.34-61.55; P = 0.02) was identified as factor associated with anti-allergy premedication options in high-risk perioperative anaphylaxis patients. Conclusion In this study, history of drug allergy and history of allergies to food or other substances were significantly associated with perioperative anaphylaxis. Avoiding culprit drugs or taking rational anti-allergy premedication was critical to prevent perioperative anaphylaxis for surgical patients with high-risk factors.